Lease Extension Calculator

Disclaimer - last updated December 2021

  1. This calculator will give you a general estimate of the premium for a lease extension for a flat. It is based on data available on a national level and does not take into account local factors that may impact on the premium.
  2. Please note that this calculator cannot do calculations for leases with less than 50 years remaining (40 years for flats in Central London).
  3. It cannot give you the actual costs. In considering the likely total cost, you should also bear in mind the leaseholder's liability for the landlord's costs. The eventual cost of the new lease will be the premium plus both your own and the landlord's "reasonable" professional costs. Stamp duty is also applicable above £125,000. These costs could be significant, so be sure to get estimates from the professionals involved (likely to be at least solicitors and surveyors) before you decide to proceed.
  4. The estimate is likely to be helpful where there is no evidence of comparable transactions. Whether another transaction is comparable for these purposes is always determined on a case by case basis.
  6. It cannot give you a definitive figure, merely an indicative value range.
  7. The estimate produced by the calculator should not be treated as a formal or professional valuation and is not a substitute for obtaining such a professional valuation. You should not take any action in reliance on the estimate without seeking formal advice from a surveyor, property lawyer or other qualified professional first.
  8. You should not use the estimate in tribunal or court proceedings and neither should you take any other action based on this information without first seeking professional advice.
  9. To the maximum extent permitted by law, we shall not be liable for any loss, injury, claim, liability or damage of any kind resulting from, arising out of or in any way related to reliance on the estimate produced by this calculator.
  10. Although we offer an advice guide, Lease extension - Valuation about valuations under the Leasehold Reform, Housing and Urban Development Act 1993 (as amended), you should remember that the law and the way property is valued can change over time and that local evidence can vary. It is therefore important that you take advice from a qualified professional such as a surveyor or property lawyer.
  11. The current priority, when assessing the short lease value, is evidence of similar flats usually in the same block or estate. Where reliable comparable sales of similar short leases can be found, that will be a better indicator and this requires extensive local knowledge beyond the scope of this national calculator. Where there is no clear evidence of short lease sale transactions, a graph approach is likely to be adopted.

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